diff options
| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2023-09-19 12:09:06 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-09-21 14:21:59 -0700 |
| commit | 3de55893f6482660e2f04454eb0e65a070523ba0 (patch) | |
| tree | d3c16cd8279574e62911e3ad1cc24cf420daa4f9 /arch/s390/net | |
| parent | 9873ce2e9c68193371c111a1a9f06064e36b9814 (diff) | |
s390/bpf: Implement BPF_MOV | BPF_X with sign-extension
Implement the cpuv4 register-to-register move with sign extension. It
is distinguished from the normal moves by non-zero values in
insn->off, which determine the source size. s390x has instructions to
deal with all of them: lbr, lhr, lgbr, lghr and lgfr.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230919101336.2223655-5-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/s390/net')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index eeb42e5cd7d6..6fb24ebb3618 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -795,15 +795,47 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, /* * BPF_MOV */ - case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */ - /* llgfr %dst,%src */ - EMIT4(0xb9160000, dst_reg, src_reg); - if (insn_is_zext(&insn[1])) - insn_count = 2; + case BPF_ALU | BPF_MOV | BPF_X: + switch (insn->off) { + case 0: /* DST = (u32) SRC */ + /* llgfr %dst,%src */ + EMIT4(0xb9160000, dst_reg, src_reg); + if (insn_is_zext(&insn[1])) + insn_count = 2; + break; + case 8: /* DST = (u32)(s8) SRC */ + /* lbr %dst,%src */ + EMIT4(0xb9260000, dst_reg, src_reg); + /* llgfr %dst,%dst */ + EMIT4(0xb9160000, dst_reg, dst_reg); + break; + case 16: /* DST = (u32)(s16) SRC */ + /* lhr %dst,%src */ + EMIT4(0xb9270000, dst_reg, src_reg); + /* llgfr %dst,%dst */ + EMIT4(0xb9160000, dst_reg, dst_reg); + break; + } break; - case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */ - /* lgr %dst,%src */ - EMIT4(0xb9040000, dst_reg, src_reg); + case BPF_ALU64 | BPF_MOV | BPF_X: + switch (insn->off) { + case 0: /* DST = SRC */ + /* lgr %dst,%src */ + EMIT4(0xb9040000, dst_reg, src_reg); + break; + case 8: /* DST = (s8) SRC */ + /* lgbr %dst,%src */ + EMIT4(0xb9060000, dst_reg, src_reg); + break; + case 16: /* DST = (s16) SRC */ + /* lghr %dst,%src */ + EMIT4(0xb9070000, dst_reg, src_reg); + break; + case 32: /* DST = (s32) SRC */ + /* lgfr %dst,%src */ + EMIT4(0xb9140000, dst_reg, src_reg); + break; + } break; case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */ /* llilf %dst,imm */ |